Trap for houseflies

ABSTRACT

An improved trap for common houseflies and many other flying insects. The device has an upright array of parallel exposed conductors dimensioned and spaced such that alighting houseflies virtually have to alight in contact with two such conductors, means to periodically apply opposing pulsating charges to adjacent pairs of such conductors which causes such houseflies to dive downwardly toward an adhesive-covered sheet or other means to receive and hold insects diving from the array. The charges are about 25 to 40 volts peak and have a frequency of about 60 to 600 Hz. Applying such charges as a square wave is very highly preferred.

FIELD OF THE INVENTION

This invention is related to the field of insect control and morespecifically to devices for trapping and killing common houseflies andother flying insects.

BACKGROUND OF THE INVENTION

A variety of devices and methods have been used to control the number ofcommon houseflies and other flying insects. Among these are chemicalsprays, evaporating insecticides, strips for capturing flies and otherinsects by means of an exposed adhesive, and electrocution devices. Eachof these devices and methods has certain advantages and drawbacks.

For example, electrocution devices are deemed undesirable because of thenoise that they cause when a spark is discharged to kill an insectpassing between two oppositely charged electrodes. Furthermore, suchdevices often are covered with partially-dried dead insects, which isunsightly and a problem to clean. Also, such devices may be dangerousbecause of the high voltage required to electrocute the insects.

Examples of devices for electrocuting insects include the disclosures ofthe following patent documents:

    ______________________________________                                        U.S. 3,935,662      U.S. 4,275,523                                            U.S. 3,894,351      U.S. 4,037,351                                            U.S. 4,109,408      U.S. 2,881,554                                            U.K. Spec. 1,444,089                                                                              France 2,411,563                                          ______________________________________                                    

German Offenlegungsschrift No. 1,607,361.

Many of the electrocution devices also include a bright light or otherinsect-attracting device. Such devices draw the insects into what isbelieved to be essentially inadvertent contact or near contact withoppositely charged electrodes. Such contact or near contact bridges ornearly bridges the gap between the oppositely charged electrodes causinga spark to jump the gap by passing through the insect.

Another type of electrical device for killing insects stuns the insectcausing it to fall into a receptacle of some kind. Examples of suchdevices are those disclosed in the following patent documents:

    ______________________________________                                        U.S. 4,423,564      U.S. 2,307,163                                            U.S. 2,038,495      Russia 547,201.                                           ______________________________________                                    

Such devices relate to the trapping and killing of crawling insects andare not concerned with control of flying insects.

Fly strips of the type having adhesives to trap flies or other alightinginsects are messy to handle, both before and after insects have beentrapped thereon. Furthermore, such strips are often very unsightly.

While insecticide sprays are very effective, some people do not want tospray in certain rooms. Evaporating chemicals which fill a space withinsecticide vapors are sometimes thought to produce undesirable odors.

In short, there is a need for an improved device to control the numberof houseflies and other flying insects in a room or other space. Thereis a need for an effective, silent, non-messy and safe device toeliminate flying insects.

BRIEF SUMMARY OF THE INVENTION

The device of this invention is a safe, silent, non-messy and effectivetrap for common houseflies and flying insects of comparable or greatersize.

The trap of this invention has an upright array of substantiallyparallel exposed conductors. Each of the conductors are of insufficientwidth to allow an adult housefly to easily alight on only one conductor,but adjacent pairs of conductors are separated by air and closely spacedsuch that an alighting housefly, in almost every case, must contact twoconductors. The device includes means to periodically generate opposingpulsating charges in adjacent pairs of the conductors, the chargeshaving about 25 to 40 volts peak (i.e., 50-80 volts peak-to-peak) and afrequency of about 60 to 600 Hz. Below the upright array of conductorsis a means to receive and hold insects diving from the array.

The conductors are preferably generally vertical wires, since flies areknown to be attracted to vertical wires. The array may have as few astwo parallel wires or may have a great many. The device preferablyincludes a fly-attracting backdrop adjacent to the array. This may be abackdrop surface of contrasting color or may be a surface of a colorknown to be attractive to houseflies, such as red or black.

The array preferably surrounds a fly-attracting core member of somekind, whether it be an attractive and/or contrasting color, ultravioletlight, feeding stimulants, aggregation pheromones or mating pheromones.The array may be configured in several ways, such as a loop of verticalparallel conductors or any other convenient shape or configuration.

The holding means at the base of the array is preferably a replaceablesheet covered with an adhesive for holding insects. Such sheet ispreferably circular. The device preferably includes a funnel above thesheet in position to direct the diving insects onto such sheet. Thedevice preferably includes a lateral wall which shields the replaceablesheet, and the insects stuck thereto, from view at least from a sidedirection.

The periodically generated charges are preferably generated for shortperiods at equal intervals, with no charges being generated in theintervening periods. For example, the charges may be generated for onesecond every thirty seconds. That gives alighting flies and otherinsects an opportunity to get well attached to a pair of conductorsbefore the charges are applied.

In highly preferred embodiments of this invention, the opposing chargesare applied as square waves. Interestingly, the use of square wavesprovides a significantly higher capture rate than sine waves or avariety of other pulsating wave forms.

This invention is based in part upon the discovery that houseflies(Musca domestica) will behave in an unexpected and unusual way whensubjected to a less than lethal electric shock of the type describedherein. When subjected to such shock, houseflies actually fly withconsiderable force in a generally downward direction, rather than simplydropping or flying off in somewhat random directions.

When attempting to escape from some perceived threat, housefliesnormally fly away in a generally backward direction. Thus, if theirheads are oriented in a downward direction, the houseflies wouldnormally fly tail-first in an upward direction, or vice versa. Or, iftheir heads are to the right, they will fly toward the left. However,with this invention, regardless of their direction of orientation on thearray of conductors, the houseflies nearly all dive with power in adownward direction.

Because the voltage applied in the device of this invention is so low,the exposed conductors can be touched without noticeable electric shock,even to a damp hand. Furthermore, because no noisy sparks are generated,the device operates silently and flies do not get stuck on theconductors. And, the preferred replaceable sheets can easily bediscarded.

OBJECTS OF THIS INVENTION

An object of this invention is to provide an improved device fortrapping and killing common houseflies and other flying insects ofcomparable or larger size.

Another object of this invention is to provide a device for killingflying insects which is silent in operation.

Another object of this invention is to provide a device for killingflying insects which is safer than devices of the prior art forelectrocuting such insects.

Another object of this invention is to provide a device for killingflying insects which is not messy in its appearance and may be cared forwith relative ease.

Another object of this invention is to provide a device forautomatically killing common houseflies and certain other flying insectswhich is effective in operation.

These and other objects will be apparent from the description ofpreferred embodiments and from the drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a flytrap in accordance with thisinvention.

FIG. 2 is a front elevation.

FIG. 3 is a top sectional taken along section 3--3 as illustrated inFIG. 2.

FIG. 4 is a side sectional taken along section 4--4 as illustrated inFIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The figures illustrate a preferred trap 10 for common houseflies andother flying insects in accordance with this invention.

Flytrap 10 includes a base cup 12 supporting a stanchion 14 sized at itslower end 16 to be received into base cup 12. Stanchion 14 includes fournarrow vertical plastic boards 18 which flare outwardly near lower end16. Above the flared portions, vertical boards 18 form a right-anglecross when viewed in top crosssection. The top of stanchion 14 isreceived in a control cap 20.

On each side of each of the four vertical boards 18 is an array 22 ofsubstantially parallel vertical wires extending from near lower end 16to above the open bottom of control cap 20. Since each of the eightarrays in this preferred embodiment are identical, only one will bedescribed in detail.

Array 22 has a first part 24 and a second part 26, each of which is anexposed conductor indirectly secured onto vertical board 18. The upperend 28 and lower end 30 of each of first and second array parts 24 and26 are each sandwiched in a plastic mounting plate 32. Mounting plates32 serve as spacers to maintain about 0.40 cm or more in spacing betweenthe wires of array 22 and the surface of plastic board 18. Mountingplates 32 at each end of array 22 are secured to vertical board 18 bybolts 36. On the opposite surface of each vertical board 18 anothersimilar array is mounted by means of the same bolts. Bolts 36 also serveto conduct the applied electrical charges between similar array parts onthe opposite surface of each board 18.

Two wire locators 34 are attached to vertical board 18 at points alongthe length of the array. Wire locators 34 serve to maintain the intendedspacing between the wires of array 22.

First part 24 of array 22 includes a bottom end portion 38 from which amain vertical wire 40 extends upwardly to a top end portion 42. Fivewires 44 extend downwardly from top end portion 42 of first array part24. Second part 26 of array 22 includes similar end portions, but withthe bottom and top portions being reversed such that second array part26 has five upwardly extending wires 46 which are between and closelyadjacent to downwardly extending wires 44, in alternating fashion. Theuse of first and second array parts 24 and 26 allows opposing charges tobe applied to every other wire.

All of wires 44 and 46 of array 22 are parallel and vertical. Each ofthese conducting wires is of insufficient width to allow an adulthousefly to easily alight on only one such conductor. Since the wires ofarray 22 are spaced from the surface of vertical board 18, adjacentpairs of wires 44 and 46 are separated only by air. The wires of eachsuch pair are closely spaced such that an alighting housefly contactsboth wires of the pair. The wires are preferably close enough to preventadult houseflies from passing easily between them.

Each vertical board 18 of stanchion 14 serves not only as means tosupport the array 22 of wires, but as a backdrop which attracts flies.The attraction occurs either because of the color of such backdrop orbecause of the visual contrast between the wires and the backdrop.Fly-attracting colors include red and black, so the use of such colorsis believed to be helpful.

The eight separate arrays 22 together form a large array surrounding afly-attracting core 48 consisting of the four boards 18 formingstanchion 14. A surrounding array can be in other forms, such as acylindrical or square form (when viewed from above).

The fly-attracting core member may have its fly-attracting qualities byvirtue of color or contrast, as noted, or because it includes a feedingstimulant (such as sugar), aggregation pheromones, mating pheromones,ultraviolet light or some other kind of stimuli. A combination offly-attracting means may be used.

Contained within control cap 20 are electrical circuit means (not shown)to periodically generate opposing pulsating charges in alternating wires44 and 46. Such charges have about 25 to 40 volts peak (50 to 80 voltspeak to peak). Higher voltages give rise to safety problems. Lowervoltages have insufficient effectiveness. A preferred voltage is about35 volts. While effective fly-catching is possible within a frequencyrange of about 60 to 600 Hz, the most preferred frequency is on theorder of 300 Hz.

It is highly preferred to apply such charges as square waves, since suchhave been shown with this invention to provide a statisticallysignificant advantage in fly-catching efficiency when compared to sinewaves.

The charges are preferably applied at equal time intervals and for equaldurations each time. For example, applying such pulsating charges onesecond at thirty second intervals has been found very acceptable. Thistiming provides flies an opportunity to get well attached to a pair ofwires but probably not depart therefrom before the pulsating charges areapplied.

The choice of what time interval to use and of how long to apply thepulsating charge depends on an number of factors. For example, ifbatteries are being used as the power source, battery life is oneimportant factor which must be considered. Other factors to considerwould be apparent to those skilled in the art and familiar with thisdisclosure.

Rather than using the preferred equal time intervals and short periodsof pulsating charge application, the device can be designed to detectthe presence of a fly or other insect of comparable or larger size onarray 22 and to trigger the pulsating charge because of such presence.

Acceptable circuit means for generating such pulsating charges are wellknown to those skilled in the art who are familiar with the disclosureof this invention. For example, when the power source is a battery(e.g., 6V or 9V), then the circuit would preferably have an appropriatesimple gated oscillating circuit, including integrated circuit chips anddiscrete capacitor(s), transistor(s) and resistor(s), and a transformerto step up the voltage. All such circuit elements can be located incontrol cap 20. Wires in control cap 20 would connect the circuitry toarray parts 24 and 26 by means of bolts 36. If the power source is housecurrent, the same circuitry can be used with the addition of anappropriate adaptor.

Placed on the inside bottom of base cup 12 below stanchion 14 isreplaceable circular sheet 50, made of paper covered with an adhesive onits exposed upper surface. The adhesive causes flies diving onto it toadhere such that they will be trapped and die. Suitable adhesives arewell-known to those skilled in the art. One example is a soft highlytacified hot melt compound known as B. F. Goodrich 490, from B. F.Goodrich, Akron, Ohio. Circular sheet 50 is sized to fit into base cup12, and may be removed and replaced by lifting stanchion 14 from basecup 12.

Secured to the outwardly flaring lower ends of vertical boards 18 is afunnel 52. Funnel 52 has an upper edge 54 defining an open upper end ofwide diameter relative to the top of base cup 12 and a lower edge ofreduced diameter which is received into base cup 12. When flies receivethe shock provided by the pulsating charge referred to above, they divein a generally downward direction to hit the funnel surface and bedirected into the base cup 12 and onto the adhesive surface of circularsheet 50. Use of the funnel allows capture of more of the diving fliescoming from wire array 22.

The trap of this invention works as follows: Flies which are attractedto stanchion 14 or array 22 alight on a pair of adjacent wires of array22. Alighting normally occurs when no charge is applied to such adjacentwires. After a few seconds has elapsed, pulsating charges are applied tothe pair of wires. This does not electrocute the fly, but instead causesit to dive forcefully in a downward direction. The fly enters the basecup 12, either directly or after being guided there after contact withfunnel 52. The fly then impacts the adhesive surface of circular sheet50 and is stuck thereon and soon perishes.

The base cup 12 includes an upright wall 56 which can shield thefly-covered adhesive sheet from view. Such shield is particularlyeffective when flytrap 10 is hanging high, such as from the ceiling of aroom. Eyelet 58 facilitates such hanging.

In some cases, particularly in embodiments for use in barns, it may bedesirable to use a bucket or jar filled with a water-surfactant solutionas the means to receive and hold insects diving from the wire array. Thesolution has low surface tension, so the insect is received into themixture to quickly drown. Other receiving and holding means may be used.

While in the foregoing specification this invention has been describedin relation to certain preferred embodiments and many details have beenset forth for purposes of illustration, it will be apparent to thoseskilled in the art that the invention is susceptible to additionalembodiments and that certain of the details described herein can bevaried considerably without departing from the principles of theinvention.

What is claimed is:
 1. A trap for trapping flies and flying insects ofcomparable size, comprising:an upright array of substantially parallel,exposed conductors, said conductors being of insufficient width to allowan adult fly to easily alight on only one conductor, wherein adjacentpairs of said conductors are separated by air and closely spaced suchthat an alighting fly contacts an adjacent pair of conductors; insectreceiving-and-holding means below said array for receiving and holdinginsects; flying insect-directing means disposed adjacent the lower endof said array and above said receiving-and-holding means for directinggenerally downwardly flying insects into contact with saidreceiving-and-holding means; and pulsing-charge means for periodicallygenerating opposing pulsating charges and delivering such charges toadjacent pairs of said conductors, said charges having about 25 to 40volts peak and a frequency of about 60 to 600 Hz, the pulsating-chargemeans being operatively connected to the conductors and adapted to causethe flies to be subjected to a less-than-lethal shock which, in turn,causes the flies to fly in a generally downward direction into theinsect receiving-and-holding means via the flying insect-directingmeans.
 2. The trap of claim 1 further including a fly-attractingbackdrop adjacent to the array.
 3. The trap of claim 1 wherein the arraysurrounds a fly-attracting core member.
 4. The trap of claim 1 whereinthe holding means is a replaceable sheet covered with an adhesive forholding insects.
 5. The trap of claim 4 wherein said directing means isfunnel shaped for directing diving insects onto the sheet.
 6. The trapof claim 4 further including a fly-attracting backdrop adjacent to thearray.
 7. The trap of claim 4 wherein the array surrounds afly-attracting core member.
 8. The trap of claim 1 wherein the chargesare applied as square waves.
 9. The trap of claim 6 wherein the deviceincludes a lateral wall shielding the replaceable sheet from view atleast from a side direction.
 10. The trap of claim 1 wherein the meansto periodically generate opposing charges generates such charges atsubstantially equal time intervals with no charges being generated inthe intervening periods.
 11. The trap of claim 8 wherein the means toperiodically generate opposing charges generates such charges atsubstantially equal time intervals with no charges being generated inthe intervening periods.